Laser markable compositions, articles and documents

A laser markable composition comprising:

• an aqueous medium;
• capsules including a polymeric shell surrounding a core;
• a color developing agent precursor;
• and
• an optothermal converting agent;
• wherein
• the core includes a leuco dye;
• and
• the color developing agent precursor is represented by Formula (I) or Formula (II):
• wherein
• R1 and R3 independently represent an optionally substituted alkyl group, an optionally substituted (hetero)cyclic alkyl group, an optionally substituted (hetero)aryl group, an optionally substituted aralkyl group, an optionally substituted alkoxy group, an optionally substituted (hetero)cyclic alkoxy group, or an optionally substituted (hetero)aryl group;
• R2, R4, and R5 independently represent an optionally substituted alkyl, an optionally substituted aliphatic (hetero)cyclic alkyl group, or an optionally substituted aralkyl group;
• and
• R1 and R2, R4 and R5, R3 and R4, and R3 and R5 may represent necessary atoms to form a ring.